50 Channel GS407 Helical GPS Receiver

Questions?

50 Channel GS407 Helical GPS Receiver

Description:Replacement:GPS-11466. This module has been updated to a u-Blox 6 chipset and uses a different on-board connector. This page is for reference only.

Combine the u-Blox chipset with Sarantel’s powerful SL1206 helical antenna and you get the impressively sensitive GS407. Whether this receiver is in your pocket or under your car seat, you are likely to pickup a rock solid GPS signal.

Hi Guys,
I’ve tried all the GPS modules of the Sparkfun website:
- This is the best GPS.
- 4Hz TRUE update rate with WAAS (or EGNOS in Europe), 5Hz without.
- Real Doppler ground speeds (3 axes : North, Est, Down)
- Completely configurable with the very easy to use Ublox UCenter software.
- You can enable / disable every single data packet.
- All the configuration can be saved to non volatile on board Flash memory.
- The optional backup battery is only here to improve Time To First Fix when started within 4 hours after last use (after, the GPS needs to download ephemerids one more time which takes 29s).
- I suggest using the proprietary data packets (binary) because it’s REALLY easier to use, it takes less CPU time, it’s already well structured for direct reading in C language, and it provides you more information (doppler speeds for example), the transmission is quicker (and then the time between measurement and transmission is shorter).
- The GPS software can be updated and the configuration can be saved on PC.
Answers to questions:
- All the NMEA data packets are available at 4Hz (but be careful, you need high speed serial transmission).
- The antenna (and then the module) has to be mounted vertically.
The only negative thing is the connector.
I recommend this module.
Antoine

I hope someone can help me out. I have a pair of these units that I would like to make into a relative or sort of homebrew differential GPS. One of my professors had a hypothesis that two of the same type of GPS would get similar errors and therefore we could easily compute a relative distance between the two GPS units with one being stationary. Anyway, I started to explore the idea and as of right now I get anywhere from 2 to 90 meters of distance between the two, while they are stationary and right next to one another (I’m talking millimeter actual distance). I plugged one of the units into my computer to check to see if it was getting the

You can certainly try it, but conventional wisdom is that there’s no practical way to do this with consumer GPS units. Here are some of the issues. An amateur radio group called TAPR designed a working DGPS system some time ago, but unfortunately the GPS module they based it on (which provided the pseudorange data that most don’t) was discontinued. Keep hacking though, this capability would be great to have!

Can anyone give me some tips on how to get this thing goin, for some reason I hook it up to 3.3V on my Arduino and the Arduino disconnects from the computer as if there is a short. Dunno what is goin on! I havent been able to get anything so far. I am using the TinyGPS code. I dont have a meter so i cant really check for shorts. But the short seems to be on the device I hope I didnt get a bad GPS??? HELP
Well its not a short just overcurrent for the 3.3V pin on the Arduino.

I have 2 identical modules. One is fine and fixes in seconds, the other communicates with u-center ok but nevers gets a fix. This seems to be a common problem over at diydrones and appears to be the quality of soldering around the antenna contacts. However to get at the contacts you need to remove the grey epoxy which is quite a tough job. Anyone had success with this approach? What tools do you use?

What is the correct voltage to supply to this unit? I have heard on other forums (DIYDrones) of people supplying 5-8V. I am supplying 3.3 V through a FTDI right now and I am able to talk to the uBlox module but I get no fixes. The various 5-8V proponents say something about it allows the Sarantel GeoHelix antenna to work?

Anyone know whether I could just desolder the u-blox 5 chip and replace it with a u-blox 6 one? I want to play around with raw pseudorange data and the u-blox 6 LEA-6 does this rather nicely. The chip outlines look the same but it would be nice to know…

Member21962 - Only the LEA-5T and -6T offer raw pseudorange. Replacing the -5H with a -6H won’t get you that. I’m trying to find a source for LEA-6T modules but haven’t had much luck. I want to find a good module to use with rtklib but so far, only the Copernicus module offers usable raw measurements.

It’s the LEA-6T I was thinking of - all the 6 series use the same pin arrangement (which looks very similar to the LEA-5 but I haven’t seen a statement anywhere saying that they more or less pin compatible). Anyway you can get the LEA-6T direct from u-blox.

Great GPS modules and test software…Once I got it working after several weeks of nothing. Gave up on serial. Removed V_USB from ground, connected tx/rx, plugged in the usb cable and worked beautifully. I dont know exactly why, but once 3.3v was applied to V_USB, the module worked.

I’ve been less impressed with GS407 compared to the GS405 (GPS-08621). I used a GS405 in my reverse geo-caching box and it it worked like a charm. While it may take longer to cold start, it was stable as a rock. Found plenty of satellites in light tree cover, the NMEA was showing strong signals from many of them, and I had no problems wiring it up to a simplistic power supply.
In my next project, I upgraded to the GS407 and it has presented me with a bunch of problems. The GS407 connector is tiny and very difficult to solder. Once I had it soldered down, I eventually lifted the traces off my pcb board because I disconnected the GPS module too many times (had to remove it to reprogram Arduino ATmega via shared serial line). I now glue it down. Even with it connected, it seems to be much more sensitive to power line jitter causing it to find few satellites with low signal and no lock. Had to add more decoupling caps and upgrading the power supply. It finally died (probably due to me shorting it somehow). The low profile connector also presents a problem as you have to mount this GPS module at the very edge of the PCB compared to the GS405 which offers much more flexibility. I’ve reclaimed the GS405 from the geocaching box and its working great.

billiam,
I can tell you that the antenna pcb is attached to the ublox chip by 5 healthy blobs of solder. I can’t tell if the pcb is also glued on, but there are no visible gaps in my module. You just want the ublox chip?

Hi Billiam, i had contacted a local distributor for the ublox and they sell the modules half the prices that you can see on ublox eshop. However, their minimum order quantity is 10. I just need a couple of units just for my hobby project. If you are interested, i will buy 10 units and sell to you the other units at same price? but you pay for shipping

From what I’ve dug off of u-blox.com:
The LEA-5H model has I2C-compatible “DDC”, USB and UART out; however, the funny pin header only has UART. You’d have to wire up to the module directly (Though that’s not hard to do, assuming they’ve left the pins floating. VDDUSB should be the only one grounded.) See “LEA-5, NEO-5, TIM-5H Hardware Integration Manual"
The LEA-5H has Windows certified drivers for the USB. (For Linux, you can use the usbserial kernel module, or others. There is a link from the usb-drivers page below to Linux instructions.)
LEA-5H Product Page: http://www.u-blox.com/en/gps-modules/pvt-modules/lea-5h.html
USB Drivers Page: http://www.u-blox.com/en/usb-drivers.html

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